Dye mixtures

ABSTRACT

A disperse dye mixture which comprises, on a weight basis, from 5% to 70% of the dye of Formula (1), from 5% to 70% of the dye of Formula (2), and from 0% to 40% of the dye of Formula (3), wherein each of R and R 1  represents an alkylene group and each of R 2  and R 3  represents an alkyl group.

This application is a 371 of PCT/GB96/01532 filed Jun. 26, 1996.

BACKGROUND OF THE INVENTION

The present invention relates to a mixture of dyes, particularly amixture of disperse polycyclic dyes, to a process for the coloration ofsynthetic textile materials and to textile materials when coloured withthe mixture of dyes.

DESCRIPTION OF THE BACKGROUND

Polycyclic dyes are known (EP 0033583 and EP 0146269) and may be appliedto synthetic textile materials by various dyeing techniques such asexhaust or continuous dyeing or printing. Generally, textile materials,when dyed or printed with such dyes, exhibit very high levels ofwet-fastness. However, it is difficult to achieve heavy shades ontextile materials with these dyes particularly when exhaust dyeing iscarried out at 130° C., the most common temperature for batch dyeingpolyester. Under these conditions, yields and levelling are usually poorand exhaustion is relatively low with much of the dye remaining in thedyebath. This poor performance can be overcome to some extent byincreasing the dyeing temperature but not sufficiently to allow troublefree dyeing.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a disperse dyemixture which comprises, on a weight basis, from 5% to 70% of the dye ofFormula (1): ##STR1## from 5% to 70% of the dye of Formula (2) ##STR2##and from 0% to 40% of the dye of Formula (3): ##STR3## wherein each of Rand R¹ represents an alkylene group and each of R² and R³ represents analkyl group.

DETAILED DESCRIPTION OF THE INVENTION

The alkylene groups represented by R and R¹ are preferably C₁₋₈-alkylene groups, more preferably C₁₋₆ -alkylene groups and especiallyC₁₋₄ -alkylene groups. It is especially preferred that R is methyleneand R¹ is methylene or ethylene.

The alkyl groups represented by R² and R³ are preferably C₁₋₈ -alkylgroups more preferably C₁₋₆ -alkyl groups and especially C₁₋₄ -alkylgroups. It is especially preferred that R² is methyl or ethyl and R³ ispropyl.

The present dye mixture has improved dyeing properties and allows heavydepths of shade to be obtained at 130° C. with improved levellingproperties and improved exhaustion over commercially available dyes.Furthermore, the dye mixture provides a commercially popular shade.

The dye mixture preferably comprises from 5% to 70%, more preferablyfrom 10% to 30%, by weight of the dye of Formula (1), from 5% to 70%,more preferably from 40% to 60%, by weight of the dye of Formula (2) andfrom 5% to 40%, more preferably from 10% to 35%, by weight of the dye ofFormula (3).

An especially preferred dye mixture comprises from 16% to 21% by weightof the dye of Formula (1), from 50% to 55% by weight of the dye ofFormula (2) and from 26% to 31 % by weight of the dye of Formula (3).

An especially preferred mixture of dyes comprises a dye of Formula (1)in which R is --CH₂ --, R¹ is --C₂ H₄ -- and R² is --C₂ H₅, a dye ofFormula (2) in which R is --CH₂ --, R¹ is --C₂ H₄ --, R² is --C₂ H₅ andR³ is n-propyl and a dye of Formula (3) in which R³ is n-propyl.

The mixture of dyes according to the invention may a be simple physicalmixture or may be mixed crystals formed, for example, byco-crystallisation or co-synthesis. Crystalline modifications ofcompounds of Formulae (1), (2) and (3) exist and it is intended that thepresent definition includes such crystalline modifications which may beformed by established treatments such as heat treatment, solventtreatment, recrystallisation or seeding.

According to a further feature of the present invention, there isprovided a process for colouring a synthetic textile material or fibreblend thereof which comprises applying to the synthetic textile materiala disperse dye mixture as hereinbefore defined.

The synthetic textile material may be selected from secondary celluloseacetate, cellulose triacetate, polyamide, polyacrylonitrile and aromaticpolyester. The synthetic textile material is preferably polyamide suchas polyhexamethylene adipamide or aromatic polyester, especiallypolyethylene terephthalate. Fibre blends may comprise mixtures ofdifferent synthetic textile materials or mixtures of synthetic andnatural textile materials. Preferred fibre blends include those ofpolyester cellulose such as polyester- cotton. The textile materials orblends thereof may be in the form of filaments, loose fibres, yam orwoven or knitted fabrics.

The mixture of dyes according to the invention, optionally inconjunction with other disperse dyes, may be applied to the synthetictextile materials or fibre blends thereof by processes which areconventionally employed in applying disperse dyes to such materials andfibre blends.

Suitable process conditions include the following:

i) exhaust dyeing at a pH of from 4 to 6.5, at a temperature of from125° C. to 140° C. for from 10 to 120 minutes and under a pressure offrom 1 to 2 bar, a sequestrant optionally being added;

ii) continuous dyeing at a pH of from 4 to 6.5, at a temperature of from190° C. to 225° C. for from 15 seconds to 5 minutes, a migrationinhibitor optionally being added;

iii) printing direct at a pH of from 4 to 6.5, at a temperature of from160° C. to 185° C. for from 4 to 15 minutes for high temperaturesteaming, or at a temperature of from 190° C. to 225° C. for from 15seconds to 5 minutes for bake fixation with dry heat or at a temperatureof from 120° C. to 140° C. and 1 to 2 bar for 10 to 45 minutes forpressure steaming, wetting agents and thickeners (such as alginates) offrom 5 to 100% by weight of the dye optionally being added;

iv) discharge printing (by padding the dye on to the textile material,drying and overprinting) at a pH of from 4 to 6.5, migration inhibitorsand thickeners optionally being added;

v) carrier dyeing at a pH of from 4 to 6.5, at a temperature of from 95°C. to 100° C. using a carrier such as methyinaphthalene, diphenylamineor 2-phenylphenol, sequestrants optionally being added.

In all the above processes, the mixture of dyes according to theinvention is applied as a dispersion comprising from 0.001% to 4% byweight of the dye mixture in aqueous medium.

Compositions comprising dispersions of the disperse dye mixture of theinvention form a further feature of the present invention. Thecompositions typically comprise from 1% to 30% by weight of a mixture ofthe dyes in an aqueous medium. The compositions are preferably bufferedat pH 2 to 7, more preferably at pH 4 to 6.

The dye dispersions may further comprise ingredients conventionally usedin coloration applications such as dispersing agents, for examplelignosulphonates, naphthalene sulphonic acid/formaldehyde condensates orphenol/cresol/sulphanilic acid/formaldehyde condensates, surfactants,wetting agents such as alkyl aryl ethoxylates which may be sulphated,sulphonated or phosphated, inorganic salts, de-foamers such as mineraloil or nonanol, organic liquids and buffers. Dispersing agents may bepresent at from 10% to 200% on the weight of the dye mixture. Wettingagents may be used at from 0% to 20% on the weight of the dye mixture.The dispersions may be prepared by bead milling the dye mixture withglass beads or sand in an aqueous medium or by combining dispersions ofmilled dyes.

Dispersions may be dried, after the addition of any extra dispersingagents, to give a solid physical form with from 5 to 60% by weight oftotal colour.

In addition to the above-mentioned application processes, the dyemixtures of the invention may be applied to synthetic textile materialsand fibre blends by ink-jet printing, the substrates optionally havingbeen pre-treated to aid printing. For ink-jet applications, theapplication medium may comprise water and a water-soluble organicsolvent, preferably in a weight ratio of 1:99 to 99:1, more preferably1:95 to 50:50 and especially in the range 10:90 to 40:60. Thewater-soluble organic solvent preferably comprises a C₁ -C₄ -alkanol,especially methanol or ethanol, a ketone, especially acetone, methylethyl ketone, 2-pyrrolidone or N-methylpyrrolidone, a glycol, especiallyethylene glycol, propylene glycol, trimethylene glycol, butane-2,3-diol,thiodiglycol or diethylene glycol, a glycol ether, especially ethyleneglycol monomethyl ether, propylene glycol monomethyl ether or diethyleneglycol monomethyl ether, urea, a sulphone, especiallybis-(2-hydroxyethyl) sulphone or mixtures thereof.

The dye mixture may also be applied to textile materials usingsupercritical fluid solvents, for example supercritical carbon dioxide,in which case the dye formulating agents may optionally be omitted.

The dyes of Formulae (1), (2) and (3) may be prepared by the processesdescribed in EP 0033583 and EP 0146269.

The invention is further illustrated but not limited by the followingExamples in which all percentages are by weight:

EXAMPLE 1

A mixture comprising 18.8% of Dye 1, 52.6% of Dye 2 and 28.6% of Dye 3was prepared and used to dye polyester textile material by an exhaustdyeing technique at 130° C. The degree of exhaustion was measured bycomparing the amount of dye initially added to the dyebath with thatremaining after dyeing, when twice the amount of dye needed to achieve a1/1 Standard Depth of shade was initially employed. Comparison was bysolution measurement using an absorption Spectrophotometer, capable ofmeasuring the concentration of dye in solution in the visible region ofthe Electromagnetic Spectrum. The degree of exhaustion was >90%.

The levelling property was assessed by measuring the reflectance of adyed piece of polyester fibre at 1/1 Standard Depth of Shade. This valuewas taken as 100%. This was compared with the reflectance from aninitially undyed piece of polyester, which was held for 1 hour at 130°C. in a blank dyebath in the presence of an identical dyed piece, andthe dye transferred to the undyed piece was expressed as a percentage ofthe original dyed piece.

Dyes 1, 2 and 3 have the structures shown below, Dye 1 being a dye ofFormula (1), Dye 2 a dye of Formula (2) and Dye 3 a dye of Formula (3):##STR4##

COMPARATIVE EXAMPLE A

A preparation using only one dye (Dye 3) was used to dye polyestertextile material under identical conditions to those used in Example 1and to an equivalent depth of shade. The degree of exhaustion was lessand the levelness of the dyeing was inferior compared with the dyemixture of the invention used in Example 1.

COMPARATIVE EXAMPLE B

A preparation using only one dye (Dye 2) was used to dye polyestertextile material under identical conditions to those used in Example 1and to an equivalent depth of shade. The degree of exhaustion was lessand the levelness of the dyeing was inferior compared with the dyemixture of the invention used in Example 1.

EXAMPLES 2-17

Further dye mixtures based on Dyes 1, 2 and 3, described in Example 1,were applied to polyester textile material under the conditionsdescribed in Example 1. There again showed superior exhaustion and leveldyeing properties compared with the single dyes used in ComparativeExamples A and B. The mixtures had the following compositions:

    ______________________________________    Example  % of Dye 1   % of Dye 2                                    % of Dye 3    ______________________________________     2       33           67         0     3       10           60        30     4       12           55        33     5       14           55        31     6       16           55        29     7       17           52        31     8       19           54        27     9       20           55        25    10       20           50        30    11       25           50        25    12       25           60        15    13       27           48        25    14       30           55        15    15       30           40        30    16       30           65         5    17       30           60        10    ______________________________________

EXAMPLE 18-42

Further mixtures of dyes were prepared. The dyes had the followingstructure, Dyes 4, 7 and 10 being dyes of Formula (1), Dyes 5, 8 and 11being dyes of Formula (2) and Dyes 6, 9 and 12 being dyes of Formula(3): ##STR5##

Mixtures of the above dyes were applied to polyester in the same manneras in Example 1, as follows:

    ______________________________________    Ex-  % of   % of   % of % of % of % of % of % of % of    amp- Dye    Dye    Dye  Dye  Dye  Dye  Dye  Dye  Dye    le   4      5      6    7    8    9    10   11   12    ______________________________________    18   12     55     33    19   16     55     29    20   14                      55   31    21          54          19        27    22          50          25        25    23                 25   20   55    24          52          17                       31    25                                     30   55   15    26   12                      55                  33    27          55          16                       29    28                 29        55        16    29                 33   12                  55    30                      16   55   29    31                                     12   55   33    32                                     16   55   29    33   27     48     25    34                      27   48   25    35                                     27   48   25    36   19                      54                  27    37   19     54                    27    38                      24   59                  17    39   18.8                    52.6                28.6    40                      18.8 52.6                28.6    41          52.6                  28.6 18.8    42                 28.6 18.8                52.6    ______________________________________

These mixtures again showed level dyeing and exhaustion propertiessuperior to the individual components.

I claim:
 1. A disperse dye mixture which comprises, on a weight basis, from 5% to 70% of the dye of Formula (1): ##STR6## from 5% to 70% of the dye of Formula (2): ##STR7## and from 0% to 40% of the dye of Formula (3): ##STR8## wherein each of R and R¹ represents an alkylene group and each of R² and R³ represents an alkyl group.
 2. The dye mixture according to claim 1 which comprises from 5% to 70% by weight of the dye of Formula (1), from 5% to 70% by weight of the dye of Formula (2) and from 5% to 40% by weight of the dye of Formula (3).
 3. The dye mixture according to claim 2 which comprises from 10% to 30% by weight of the dye of Formula (1), from 40% to 60% by weight of the dye of Formula (2) and from 10% to 35% by weight of the dye of Formula (3).
 4. The dye mixture according to claim 3 which comprises from 16% to 21% by weight of the dye of Formula (1), from 50% to 55% by weight of the dye of Formula (2) and from 26% to 31% by weight of the dye of Formula (3).
 5. The dye mixture according to claim 1 wherein in the dye of Formula (1) R is --CH₂ --, R¹ is --C₂ H₄ -- and R² is --C₂ H₅, in the dye of Formula (2) R is --CH₂ --, R¹ is --C₂ H₄, R² is --C₂ H₅ and R³ is n-propyl, and in the dye of Formula (3) R³ is n-propyl.
 6. The dye mixture according to claim 1, wherein said dye of the formula (1) or formula (2) is in crystalline form.
 7. The dye mixture according to claim 1, wherein said dye of the formula (1) and said dye of the formula (2) are each in crystalline form.
 8. The dye mixture according to claim 2, wherein said dye of the formula (1), (2) and (3) are each in crystalline form.
 9. The dye mixture according to claim 1, wherein R and R¹ are each C₁ -C₄ alkylene, and R² and R³ are each C₁ -C₄ alkyl.
 10. A composition comprising from 1% to 30% by weight of a dye mixture as defined in claim 1 dispersed in an aqueous medium.
 11. The composition according to claim 10 containing 1% to 30% by weight of a dye mixture, wherein said dye mixture comprises 5 to 70% by weight of the dye of Formula (1), 5 to 70% by weight of the dye of Formula (2), and 5 to 40% by weight of the dye of Formula (3).
 12. The composition according to claim 10, which is buffered at a pH of 2 to
 7. 13. The composition according to claim 12, which is buffered at a pH of 4 to
 6. 14. A process for colouring a synthetic textile material or fiber blend thereof which comprises applying to the synthetic textile material of fiber blend thereof a dye mixture as defined in claim
 1. 15. The process for coloring a synthetic textile material or a fiber blend thereof comprising applying to the synthetic textile material or fiber blend thereof a dye mixture as defined in claim
 2. 16. The process according to claim 14, wherein said synthetic textile material or fiber blend thereof is selected from the group consisting of secondary cellulose acetate, cellulose triacetate, polyamide, polyacrylonitrile and aromatic polyester.
 17. The process according to claim 16, wherein said polyamide is polyhexamethylene adipamide.
 18. The process according to claim 16, wherein said aromatic polyester is polyethylene terephthalate.
 19. The process according to claim 14, wherein said dye mixture is applied as a dispersion comprising from 0.001% to 4% by weight of the dye mixture in aqueous medium. 